Molten carbonate fuel cells (MCFCs) are power generating units that are drawing attention as the upcoming renewable energy because MCFCs have high power generating efficiency of about 47% and low fuel consumption and carbon gas emission. Since MCFCs with a Li/Na electrolyte uses a molten carbonate electrolyte to generate carbonate ions that react with hydrogen, the MCFCs may operate at a high temperature of about 650° C.
Such a MCFC may generate waste heat having a temperature of about 350° C. while operating. Thus, the MCFC may be interlocked with a heat recovery unit (HRU) by using the generated waste heat. Here, the HRU may be a unit that recovers residual heat of exhaust gases or discharged hot water to supply cooling/heating air and hot water. That is, the HRU may represent heat equipment for heat generation, heat transport, heat use, heat exchange, and the like.
In recent years, a 100 kW class MCFC that has been developed to respond to the load of a single building is linked with the HRU to supply cooling/heating air and hot water, which are used in the building. Thus, methods for increasing generation efficiency of the MCFC to about 50% to about 60% are being required.